Electricity Mix Based on Power Purchase Agreements: There are non-technical people talking about the “Vermont electricity mix” or the “New Hampshire electricity mix”. That mix exists only on paper, because it is based on power purchase agreements, PPAs, between utilities and owners of electricity generators. A utility may claim it is 100% renewable. This means the utility has PPAs with owners of renewable generators, i.e. wind, solar, biomass, hydro, etc. That mix has nothing to do with physical reality.
Electricity Mix Based on Physical Reality: Once electricity is fed into the NE electric grid by any generator, it travels:
- On un-insulated wires, as electromagnetic waves, EM, at somewhat less than the speed of light, i.e. from northern Maine to southern Florida, about 1800 miles in 0.01 of a second, per College Physics 101.
- On insulated wires, the speed decreases to as low as 2/3 the speed of light, depending on the application.
If those speeds were not that high, the NE electric grid would not work, and modern electronics would not work.
The electrons vibrate at 60 cycles per second, 60 Hz, and travel at less than 0.1 inch/second; the reason it takes so long to charge a battery.
It is unfortunate most high school teachers told students the electrons were traveling.
Teachers likely never told them about EM waves, or did not know it themselves.
This article explains in detail what happens when electricity is fed to the grid.
NOTE: If you live off the grid, have your own PV system, batteries, and generator for shortages and emergencies, then you can say I use my own electricity mix. If you are connected to the GMP grid, which is connected to the NE grid, and draw from any socket, then you draw the NE mix.
All of New England has the Same Electricity Mix: Based on the above, all of NE has the same electricity mix, i.e., there is not one mix for VT, another for NH, or one mix for the Netherlands, another for Germany.
RE-Promoter Claim: Some RE promoters absurdly claim a state, such as Vermont, has its very own energy mix, and “If it gets generated in Vermont, it gets consumed in Vermont.” That is total nonsense, because the electricity would spread out from its point of generation at somewhat less 180 miles in all directions in 0.001 of a second, as it is being consumed, well beyond Vermont’s borders. To aver otherwise displays ignorance of Physics or deliberate deception.
The RE-promoter claim locally-generated RE fed into the grid is locally consumed is a feel-good, RE-promoting ploy to make lay people think they are consuming their locally generated RE. That claim has nothing to do with physical reality. Government entities even use that ploy as a basis for making analyses for showing the benefits of RE, for awarding subsidies, and for giving other preferential treatment.
Grid is Dependent on Synchronous Rotational Inertia: The grid, completely dependent for its stability on the plentiful, synchronous rotational inertia of the traditional generating plants, could not function unless the generator EM waves were 1) synchronized, i.e., having the same frequency, 60 Hz, as the grid, and 2) in phase with the phase of the grid; having too much variation of frequency and phase would immediately trip a generator off line, even though it appears to be at near-synchronous speed. Grid operators, such as ISO-NE, require varying frequencies, voltages and positive reactive power factors of generators be maintained within narrow ranges to avoid cascading grid outages. Grid instability, and even utter chaos, would ensue otherwise.
Positive and Negative Reactive Power: On transmission lines, reactive power maintains the voltage on the line so the active power can flow to do useful work. Reactive power is compensated by external means. Typically, a capacitor (to supply reactive power to increase voltage profile), or an inductor (to absorb reactive power to decrease voltage profile) is connected in parallel to the transmission line.
Preparing to Synchronize a Generator to the Grid: This article, prepared by General Electric, describes in detail the requirements of connecting a generating plant, such as Lowell, to the grid. See URL.
Example of Variable Wind Energy Disturbing the Grid: In case of the Vermont Lowell Mountain wind turbine plant, 63 MW, the deviations outside required frequency and voltage ranges, and the varying, negative reactive power factor were too excessive for the grid operator, ISO-NE, to allow the electricity to be fed, via a substation, into the high voltage electric grid; taking reactive power from the grid decreases grid stability.
GMP, the owner, was ordered to curtail output and to install a $10.5 million, 62-ton, synchronous-condenser system, which took over one year, to provide:
1) The required stability of frequency and voltage, and a controllable, positive reactive power factor (adding reactive power to the grid increases grid stability), and
2) Synchronous rotational inertia, as do all other traditional plants.
Total capital cost to connect to the grid was about $20 million, including the synchronous-condenser system. The cancelled 60 MW Seneca wind turbine plant, proposed to be located nearby, would have required $67 million to connect to the grid.
Obtaining electricity on a Physical Basis: On a physical flow basis, anyone drawing from the grid gets a generic quantity of electromagnetic waves that travelled at somewhat less than 1800 miles in 0.01 second to get to your socket.
Claiming Electricity on a Contracted Basis: On a contracted basis, any entity can CLAIM be 100% renewable regarding electricity, such as the Burlington Electric Department in Vermont. However, every entity must have a contract, usually called power purchase agreement, PPA, to be authorized to draw from the grid, otherwise it would be stealing.
- Utility-owned meters to measure the quantity of electricity drawn from the grid are used to monitor ratepayers.
- Distributing/producing utilities, such as GMP, have PPAs with various entities that produce or resell electricity, such as independent electricity producers. Those contracts entitle a utility to draw a generic quantity of electricity (MW, MWh) from the grid as needed, or as proscribed by the contract.
Artificial Labeling of Electricity: A grid-connected solar system feeds its output to the grid. Once fed to the grid, the electricity is indistinguishable from any other electricity fed to the grid; it all travels, as EM waves, at somewhat less than the speed of light.
People do assign artificial labels to fractions of the electricity fed to the grid, such as calling it renewable, or wind, or solar, etc., for claiming purposes, which lay people tend to confuse with the physical electricity.
That confusion is an ideal situation for Madison Avenue types to exploit to the max the deluding of lay people and keep them uninformed in la-la-land, while various multi-millionaire hucksters, with Wall Street-inspired, risk-free, tax shelters, rob us blind.
Deceptive Logic of the Dutch: The Netherlands’ national railway company, NS, has announced all of its electric passenger trains (not the freight trains) are now 100% powered by wind electricity. At first the company enthusiastically announced “all electric trains”, but later corrected it to “all electric passenger trains”. Many of its trains are electric and diesel freight trains.
The Dutch and other people draw electricity from the European grid, which has been generated by many sources. Everyone drawing from the grid is equal, on a physical basis, because grids are interconnected.
The railway company has PPAs to buy only from renewable electricity producers, and thus claims, our passenger trains run on renewable electricity, but fails to add “on a contract basis”.
It is just another way for pro-RE folks to bamboozle the lay public and keep the green mythology alive.
BTW, the only way to be “all-green” is to draw electricity from the Iceland grid (all geothermal), if energy embodied in the Iceland, mostly imported, electricity system is ignored.